John Cleese

They don't. Or if they do, it's because they seem to be . opposites. But what really draws people together is their similarities, and moreover a similarity in one of the most fundamental aspects of all – that of their family backgrounds.

I know that you, as a psychiatrist, are used to the idea of the influence that unconscious forces have on people's behaviour but it's a bit of a shock for a layman like me to realise, quite suddenly, how much we're doing things for reasons we're not aware of.

And these habitual emotions will show themselves in posture, facial expressions and the typical way they move. Take a depressive person. He'll tend to slump and slouch and move apathetically. And by virtue of having his face in a depressed expression over the years, he'll develop certain facial lines which we recognise immediately. The same applies to a cheerful fellow who smiles a lot – he'll get laugh lines, and will usually move in a more positive, eager, upright kind of way; somebody a bit manic will move jerkily and seem tense and tend to have rather staring eyes.

Well you see, each family tends to have a particular way of handling emotions. They'll all tend to think some emotions are 'good' and some 'bad'. So they'll be open about expressing the 'good' ones and very guarded about the 'bad' ones. Or they may keep a stiff upper lip about emotions in general, or a completely floppy one. The result is that each family develops a characteristic set of emotional attitudes, so the members of that family will all share the same emotional habits.

Is that why dogs tend to look like their owners?

Robin Yes, there's a lot of truth in that. The pets get treated according to the family attitudes. So families which believe in self-control will have obedient dogs and families which don't and have rather wild children will excite their dogs to behave in the same way.

So to sum up . . . we signal, by our expressions, postures and ways of moving, certain habitual emotional attitudes we have, which we share with other members of our family. And people from similar families will pick them up and respond to them.

Robin Exactly. That's what the Family Systems Exercise shows.

You can look at life as a series of stages we have to pass through. And as we go through each stage, we learn certain lessons. In fact, we may need to learn the lessons of one stage before we can pass on properly to the next.

John Give me examples of some of the earlier stages.

Robin Well, we all need to have consistent, reliable love and care when we're children. The mother usually plays the most important part in this when we're very young, of course.

John And what do we learn from that?

Robin Well, if our mothers haven't been able to care for us properly, we haven't learned how to take care of others.

A lot of learning isn't conscious, you know. Especially in childhood, when most learning is copying, modelling yourself on people, particularly the parents, of course. So if they don't give you an experience, it's harder later for you to provide it for others, harder to know if you're getting it right.

Self-discipline. Without that, we'll never get a good relationship with authority. We won't be able to accept it easily, we'll resent it, and even the need for it. Also, if we're ever placed in a position where we have to exert authority, we'll find it difficult. We'll tend to vacillate between being too weak and indecisive and suddenly acting arbitrarily and being too rigid, to show we really are strong.

Whereas if the parents have exercised authority lovingly and firmly . . . ?

Robin Then, when that person's grown up, they'll be able to consult everyone fully and then take a decision and stick to it; although they'll also be able to change their mind if it becomes apparent they've made a mistake.